Abstract

BACKGROUND:

Adult dogs with degenerative myelopathy (DM) have progressive ataxia and paresis of the pelvic limbs, leading to paraplegia and euthanasia. Although most commonly reported in German Shepherd dogs, high disease prevalence exists in other breeds.

RESULTS:

Median duration of clinical signs before euthanasia was 19 months. Median age at euthanasia was 13 years. All dogs were nonambulatory paraparetic or paraplegic, and 15 dogs had thoracic limb weakness at euthanasia. Electrodiagnostic testing and spinal imaging were consistent with noncompressive myelopathy. No significant difference was detected in 8-isoprostane concentrations between normal and FDM-affected dogs. Axonal and myelin degeneration of the spinal cord was most severe in the dorsal portion of the lateral funiculus. Pedigree analysis suggested a familial disease.

CONCLUSIONS AND CLINICAL IMPORTANCE:

Clinical progression of FDM in PWC dogs was similar to that observed in other breeds but characterized by a longer duration. Spinal cord pathology predominates as noninflammatory axonal degeneration. Oxidative stress injury associated with 8-isoprostane production is not involved in the pathogenesis of FDM-affected PWC dogs. A familial disease is suspected.